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Late Quaternary sinistral slip rate along the Altyn Tagh fault and its structural transformation model

Science China Earth Sciences 2005年第3期48卷 384-397页

作者： P. Tapponnier J. Van Der Woerd F. J. Ryerson A.S. Meriaux Laboratoire de Tectonique Institut de Physique du Globe de Paris FranceLaboratoire de Tectonique Institut de Physique du Globe de Paris FranceIGPP Lawrence Livermore Laboratory Livermore CA 94550 USALaboratoire de Tectonique Institut de Physique du Globe de Paris France

Based on technical processing of high-resolution SPOT images and aerophotos, detailed mapping of offset landforms in combination with field examination and displacement measurement, and dating of offset geomorphic surfaces by using carbon fourteen (14C), cos- mogenic nuclides (10Be+26Al) and thermoluminescence (TL) methods, the Holocene sinistral slip rates on different segments of the Altyn Tagh Fault (ATF) are obtained. The slip rates reach 17.5 ±2 mm/a on the central and western segments west of Aksay Town, 11±3.5 mm/a on the Subei-Shibaocheng segment, 4.8±1.0 mm/a on the Sulehe segment and only 2.2±0.2 mm/a on the Kuantanshan segment, an easternmost segment of the ATF. The sudden change points for loss of sinistral slip rates are located at the Subei, Shibaocheng and Shulehe triple junctions where NW-trending active thrust faults splay from the ATF and propagate southeastward. Slip vector analyses indicate that the loss of the sinistral slip rates from west to east across a triple junction has structurally transformed into local crustal shortening perpendicular to the active thrust faults and strong uplifting of the thrust sheets to form the NW-trending Danghe Nanshan, Daxueshan and Qilianshan Ranges. Therefore, the eastward extrusion of the northern Qing- hai-Tibetan Plateau is limited and this is in accord with “the imbricated thrusting transforma- tion-limited extrusion model”.

关键词： Altyn Tagh Fault, sinistral strike-slip rate, structural transformation, extrusion tectonics.

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Nucleation barrier of fcc(γ)→hcp(ε) martensitic transformation in Fe-based alloys

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Science China(Technological Sciences) 2004年第1期47卷 121-128页

作者： HUANG Xing CHEN Shipu School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200030 China School of Materials Science and Engineering Shanghai Jiao Tong University Shanghai 200030 China

Based on the dislocation theory and Olson's stacking fault model, a model describing the nucleation of an hcp(ε) martensite embryo at low-angle grain boundary is proposed with the influence of external stress field taken into account. The dependences of temperature (T), shear stress (τ) and dislocation density at grain boundary on the martensite nucleation in FeMnSi based alloy, as an example, are numerically simulated. It has been shown that there exist the subcritical and critical embryos during the course of ε-phase nucleation. The free energy difference between them is just the energy barrier of embryo growth. Depending on T and τ. the characteristic embryo sizes may vary in wide ranges and decreases with increasing σ and decreasing T. The energy condition of martensitic transformation at M s and critical shear stress (τc) is discussed from the viewpoint of kinetics and thus the TEM observed result that stacking fault energy is not zero at M s temperature is reasonably explained. Besides, it is predicted that the high dislocation density at grain boundary can promote the nucleation of fcc→hcp transformation in Fe-based alloys.

关键词： martensitic transformation, stacking fault mechanism, nucleation, energy barrier, temperature, stress, dislocation density.

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Spectral transformation of constant mean curvature surfaces in H^3 and Weierstrass representation

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Science China Mathematics 2002年第8期45卷 1066-1075页

作者：陈卿程艺 Department of Mathematics University of Science and Technology of China Hefei China

By using the method of integrable system, we study the deformation of constant mean curvature surfaces in three-dimensional hyperbolic space form H3. We also obtain a Weierstrass representation formula of the constant...

关键词： hyperbolic space, mean curvature, spectral transformation, Weierstrass representation formula.

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The Darboux transformation for NLS-MB Equations

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Communications in Theoretical Physics 2002年第10期38卷 493-496页

作者： HE Jing-Song CHENG Yi LI Yi-Shen Department of Mathematics University of Science and Technology of China Hefei 230026 China Department of Mathematics University of Science and Technology of China Hefei 230026 China Department of Mathematics University of Science and Technology of China Hefei 230026 China

The Darboux transformations for the nonlinear Schrodinger equation and Maxwell-Bloch equations areconstructed. The one-soliton solution and periodic solution are obtained from the different "seeds".

关键词： Darboux transformation, NLS-MB equations, soliton

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Solving Generalized Non-degenerate Two-Mode Two-Photon Jaynes-Cummings Model by Supersymmetric Unitary transformation

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Communications in Theoretical Physics 2002年第7期38卷 85-88页

作者： SONG Tong-Qiang ZHU Yue-Jin Department of Physics Ningbo University Ningbo 315211 China Department of Physics Ningbo University Ningbo 315211 China

Based on supersymmetric quantum mechanics theory, we introduced a supersymmetric unitary transfor mation to diagonalize the Hamiltonian of non-degenerate two-mode two-photon Jaynes-Cummings models which include any forms of intensity-dependent coupling, field-dependent detuning, and field nonlinearity. Its eigenvalue, eigenstates,and time evolution of state vector are obtained.

关键词： supersymmetric unitary transformation, Jaynes-Cumnings model

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A New Expression of the Fractional Fourier transformation

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Communications in Theoretical Physics 2001年第10期36卷 399-400页

作者： YU Zu-Rong Department of Applied Physics Shanghai Jiao Tong University Shanghai 200030 China

With the help of su(2) algebra technique, a new equivalent form of the fractional Fourier transformation is given. Two examples are illustrated for their physical application in quantum optics.

关键词： su(2) algebra, the fractional Fourier transformation, squeezed state, Wigner operator

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A hyperspectral image compression algorithm based on wavelet transformation and fractal composition (AWFC)

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Science China(Technological Sciences) 2006年第Z2期49卷 48-56页

作者： HU Xingtang ZHANG Bing ZHANG Xia ZHENG Lanfen TONG Qingxi State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China State Key Laboratory of Remote Sensing Science Jointly Sponsored by the Institute of Remote Sensing Applications of Chinese Academy of Sciences and Beijing Normal University Beijing 100101 China

Starting with a fractal-based image-compression algorithm based on wavelet transformation for hyperspectral images, the authors were able to obtain more spectral bands with the help of of hyperspectral remote sensing. Because large amounts of data and limited bandwidth complicate the storage and transmission of data measured by TB-level bits, it is important to compress image data acquired by hyperspectral sensors such as MODIS, PHI, and OMIS; otherwise, conventional lossless compression algorithms cannot reach adequate compression ratios. Other loss-compression methods can reach high compression ratios but lack good image fidelity, especially for hyperspectral image data. Among the third generation of image compression algorithms, fractal image compression based on wavelet transformation is superior to traditional compression methods,because it has high compression ratios and good image fidelity, and requires less computing time. To keep the spectral dimension invariable, the authors compared the results of two compression algorithms based on the storage-file structures of BSQ and of BIP, and improved the HV and Quadtree partitioning and domain-range matching algorithms in order to accelerate their encode/decode efficiency. The authors' Hyperspectral Image Process and Analysis System (HIPAS) software used a VC++6.0 integrated development environment (IDE), with which good experimental results were obtained. Possible modifications of the algorithm and limitations of the method are also discussed.

关键词： wavelet transformation, fractal coding, image compression, hyperspectral image, HIPAS.

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Helicobacter pylori acquisition of metronidazole resistance by natural transformation in vitro

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World Journal of Gastroenterology 1998年第5期4卷 22-24页

作者： HUA Jiesong 1, ZHENG Peng Yuan 1, Teo Keng Fong 1, Khin Mar Mar 2 and HO Bow 1

AIM To study whether Helicobacter pylori is naturally transformable. METHODS transformation was performed in BHI broth supplemented with horse serum and yeast extract. Genomic DNA extracted from a metronidazole resistant H. pylori strain was added to H. pylori broth culture. The mixture was incubated at microaerophilic atmosphere. The DNA treated cells were plated on blood agar containing 8mg/L metronidazole to select for transformants. Sterile distilled water was used as a negative DNA control. The DNA profiles of transformants were compared with that of their parent strains by randomly amplified polymorphic DNA (RAPD) fingerprinting. RESULTS transformation of H. pylori with DNA from a metronidazole resistant strain as a marker was demonstrated. Out of the 12 strains of H. pylori tested, 9 (75%) strains were found to be transformable. The transformation frequencies ranged from 3 4×10 -6 to 2 4×10 -4 . By RAPD, DNA fingerprints of the transformants and their parent strains showed no change in DNA profiles though transformants were all resistant to metronidazole as compared with their metronidazole sensitive parent strains. CONCLUSION Helicobacter pylori is naturally transformable which might be one of the ways that H. pylori develops resistance to metronidazole.

关键词： Helicobacter pylori metronidazole drug resistance, microbial transformation, bacterial

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Physical Simulation of Thermally Induced Martensite Formation from Retained Austenite in TRIP Steels

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Journal of Materials Science & Technology 2003年第z1期19卷 105-108页

作者： Lie ZHAO Fred J. VERMOLEN Jilt SIETSMA Sybrand van der ZWAAG Netherlands Institute for Metals Research P.O.Box 5008 2600 GA Delft The Netherlands Department of Materials Science Delft University of Technology R otterdamseweg 137 2628 AL Delft The Netherlands Department of Applied Mathematics Delft University of Technology Mekelweg 4 2628 CD Delft The Netherlands Department of Materials ScienceDelft University of TechnologyRotterdamseweg 1372628 AL DelftThe Netherlands Netherlands Institute for Metals Research P.O.Box 5008 2600 GA Delft The Netherlands Faculty of Aerospace Engineering Delft University of Technology Kluyverweg 1 2629 HS Delft The Netherlands

The present work analyses the total free energy of the material during the martensitic transformation. A general expression for the martensite fraction as a function of temperature is derived, assuming that the nonchemical free energyis proportional to the volume of martensite. This expression indicates that the temperature-dependent martensitefraction can be predicted once the characteristic transformation temperatures and the relation between the chemicalfree energy and temperature of the martensite and austenite are known. An advantage of this development is thatthe proposed equation is valid for all types of relations between the chemical free energy and temperature. Thissimulation is successfully applied to the martensitic transformation upon further cooling of retained austenite in alow-alloyed TRIP steel, in which the relation between chemical free energy and temperature is quadratic and thefraction is determined from a thermo-magnetic measurement.

关键词： Thermodynamics, Martensitic transformation, Retained austenite, TRIP steels.

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The structural stability in nano-sized crystals of metals

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Science China(Technological Sciences) 2002年第5期45卷 485-494页

作者：孟庆平戎咏华徐祖耀 Sch. of Mat. Science and Engineering Shanghai Jiaotong University Shanghai 200030 China

The equation of phase equilibria in nano-sized crystal of metals has been established in terms of thermodynamic equilibrium. The thermodynamic parameters are calculated and the critical grain size for the stable high-temperature phase at room temperature is obtained. As an example, the critical grain size of β-Co at room temperature is determined at 35nm when the excess volume is 10%. The result agrees well with the experiment of Katakimi et al. The factors affecting the stability of β-Co are also discussed.

关键词： phase transformation, nano-sized crystal, energy of interface, critical size, excess volume.

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